FIG. 6 is a diagram illustrating a conventional elevator door safety device. In this FIG. 6, (101) represents an entrance on a hoistway side. At this entrance (101), doors (102) and (103) which slide open on both sides are arranged. An entrance (104) on the car side faces entrance (101) on the hoistway side. At this entrance (104), doors (105) and (106) which slide open on both sides are arranged.
On car side doors (105) and (106), safety shoes (108) and (109) reverse the movement of doors (105), (106), (102), and (103) when they come in contact with passengers. A light-emitting element (110) and a light-receiving element (111) are installed as a photodetector on the safety shoes. When the photodetectors also detect the passengers, the movement of doors (102), (103), (105) and (106) reverses.
Because of cost and other considerations, safety shoes (108) and (109) and photodetectors (110) and (111) are installed on the door side instead of the hoistway side.
When the car reaches the hoistway landing, car side doors (105) and (106) and hoistway side doors (102) and (103) engage via engagement parts (not shown in the figure), and, when car side doors (105) and (106) open/close, hoistway side doors (102) and (103) also open/close in known interlocked fashion.
For this conventional elevator door safety device, the photodetectors (110) and (111) are arranged on the car side instead of the hoistway side. Therefore, when doors (102), (103), (105) and (106) are being closed, if some passengers (such as children or the elderly) enter the car slowly, hoistway side doors (102) and (103) may be in contact with the passengers before the passengers are detected by photodetectors (110) and (111). This may be dangerous.